Chromatography, as it is generally used, is a technique for the separation of various components of a "sample mixture". In a liquid chromatography system, a sample followed by an elution fluid is injected into a chromatographic separation column. The separation column contains a packing or matrix medium or material which interacts with the various components of the sample fluid to be separated. The composition of the separating medium depends on the fluid being directed therethrough to effect the desired separation. As the sample and elution fluids pass through the separating matrix or medium, the various components of the sample fluid travel at different rates through the separating medium or matrix as a result of differential interactions with the separating medium or matrix. Consequently, these components emerge separated (different elution times and different R.sub.f values) in the outlet or effluent from the separation medium or matrix, as is well known in the art.
Thin layer chromatography, is one of the chromatographic techniques developed from paper chromatography, and is widely used for separating the different components in a complex mixture. The technique, generally, comprises the transfer of a sample material to be analyzed to a spot or spots on the chromatographic plate or sheet, drying the deposited sample, and initiating the differential migration of the various components of the sample material by flowing appropriate solvent or solvents across the surface of the plate, in vertical, horizontal, circular or anticircular modes. In the vertical mode, the solvent travels up or down the plate or sheet. In the horizontal mode, the solvent travels from one side to the other side of the plate or sheet. In the circular mode, the solvent travels from the center outward in all directions and in the anticircular flow thin layer chromatography, the solvent travels from the periphery to the center of the sorption layer.
Various types of the vertical flow separation columns and other thin layer chromatographic techniques are known in the art and are exemplified by the following patents.
U.S. Pat. No. 4,388,193 issued June 14, 1983 to Paul Buncak discloses a thin layer chromatographic method where a pressurized, developing solvent is conducted from a dosing container directly on to the sorption layer through an exit opening and thence to a surface slit.
U.S. Pat. No. 4,351,800 issued Sept. 28, 1982 to R. H. Kopp et al., describes an apparatus for the application of multiple samples to thin layer chromatographic plates.
U.S. Pat. No. 4,346,001, issued Aug. 24, 1982 to E. Tyihak et al., discloses an over-pressurized thin layer chromatographic apparatus where the sorption layer vs covered by a membrane which is filled and externally pressurized by a fluid medium. A transparent cover plate provided with sealed inlets is fitted over the membrane and serves to introduce sample and solvent to the sorption layer through the membrane.
U.S. Pat. No. 3,928,203 issued Dec. 23, 1975 to R. D. Kremer is directed to a thin layer chromatography apparatus which includes a sorption layer on which a plurality of sample spots may be positioned. A base plate providing a plurality of solvent wells and a wick holding plate for transferring the solvent from the solvent wells to the sorption layer are employed.
U.S. Pat. No. 4,469,601 issued Sept. 4, 1984 to L. A. Beaver et al., describes a system and apparatus for multi-dimensional real-time chromatography.
U.S. Pat. No. 4,604,198 issued Aug. 5, 1986 to N. Dailey et al., discloses a multicartridge chromatography housing.
In all these prior techniques, the eluted sample patterns need to be separately developed or eluted off the plate or sheet for further analysis. The thin layer chromatographic (TLC) systems described in the above described patents, are designed to speed up and enhance analysis of the compounds have to be separated. In all these methods, detection of the separated constituents is done by means of traditional TLC methods such as staining, scanning the TLC plate surface and the like. These prior art methods, therefore, do not readily lend themselves to operation in the High Performance Liquid Chromatography (HPLC) mode or for handling at one time or in a continuous fashion, large quantities of sample material to be separated.
A horizontal flow chromatography system is described in U.S. Pat. No. 4,627,918 reference to which was made earlier.
With the need for high performance chromatography, horizontal flow type chromatographic columns were developed. Such horizontal or radial flow columns are described and claimed in the earlier referenced U.S. Pat. Nos. 4,627,918 and 4,676,898. In the horizontal or radial flow type columns, the sample and elution fluids are introduced via a distributor to the outer periphery or circumferential wall or surface of the separating medium or matrix, and the fluids pass horizontally or radially inwardly through the separation medium to a central or collection port and then elute from the column at different times and at different rates.
Various types of horizontal flow type columns have been recently developed. Such columns include those of a disposable type or of the type which utilize a disposable medium. Copending applications Ser. No. 869,295, now U.S. Pat. No. 4,676,898 issued June 30, 1987, Ser. No. 904,912, now U.S. Pat. No. 4,740,298 issued Apr. 26, 1988, and Ser. No. 906,646, now U.S. Pat. No. 4,708,782, issued Nov. 24, 1987 referenced herein earlier, disclose and claim liquid chromatographic column which utilize a disposable type separation medium or matrix. Copending applications Ser. No. 904,912, now U.S. Pat. No. 4,740,298 issued Apr. 26, 1988, and Ser. No. 906,646, now U.S. Pat. No. 4,708,782, issued Nov. 24, 1987 also describe and claim a "wafer" of or a thin matrix-supported separation medium. While the horizontal or radial flow type columns described therein enable the handling of high flow rates at relatively low operational pressures without sacrificing the desired high resolution, there still exists a need for more simplified separation and/or fluid distribution systems which provide high resolution, and for methods and means for producing them less expensively.
Accordingly, it is an object or this invention to provide an improved horizontal or radial flow chromatography column.
A further object is to provide an improved thin layer chromatography system utilizing radial or horizontal flow.
Another object of the invention is to provide a liquid chromatography column with an improved fluid distribution system.
Still another object of the invention is to provide a simplified but sturdy fluid inlet distribution arrangement for thin layer or thin matrix type chromatography systems which utilize horizontal or radial flow.
Yet another object of the invention is to provide a less expensive horizontal flow chromatography column or system which utilizes an improved fluid system and a "wafer" type separation medium or matrix.
A further object is to provide for a means of continuous removal and on line detection of the separated constituents from the chromatography column.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.